We deployed three eddy covariance towers along a burn severity gradient (i.e. severely-, moderately-, and un-burned tundra) to monitor post fire Net Ecosystem Exchange of CO2 (NEE) within the large 2007 Anaktuvuk River fire scar during the summer of 2008. This data represents the first post fire growing season's energy and mass exchange at the severe burn site.

We deployed three eddy covariance towers along a burn severity gradient (i.e. severely-, moderately-, and un-burned tundra) to monitor post fire Net Ecosystem Exchange of CO2 (NEE) within the large 2007 Anaktuvuk River fire scar during the summer of 2008. This data represents the 2012 post fire energy and mass exchange at the severe burn site.

The Anaktuvuk River Fire occurred in 2007 on the North Slope of Alaska. In 2008, three eddy covariance towers were established at sites represent ing unburned tundra, moderately burned tundra, and severely burned tundra. During the 2008-2014 growing seasons, canopy vegetation within the footprint of each of these towers was scanned with a handheld spectrophotometer several times throughout the growing season. Average reflectance spectra per site and collection day are presented here.

We deployed three eddy covariance towers along a burn severity gradient (i.e. severely-, moderately-, and un-burned tundra) to monitor post fire Net Ecosystem Exchange of CO2 (NEE) within the large 2007 Anaktuvuk River fire scar during the summer of 2008. This data represents the 2010 post fire energy and mass exchange at the severe burn site.

We deployed three eddy covariance towers along a burn severity gradient (i.e. severely-, moderately-, and un-burned tundra) to monitor post fire Net Ecosystem Exchange of CO2 (NEE) within the large 2007 Anaktuvuk River fire scar during the summer of 2008. This data represents the first post fire growing season's energy and mass exchange at the unburned site.

Aboveground plant and belowground stem biomass were measured in moist acidic and moist non-acidic tussock tundra experimental plots. Treatments at the acidic site include control and nitrogen (N) plus phosphorus (P) amendments; treatments at the non-acidic site include N, P, N+P, greenhouse warming, and greenhouse+N+P.

Note: Version 8 corrected an error where Carex vaginata was listed twice under treatment of "Nitrogen Phosphorus". The tissues with 8 quadrats were "Greenhouse" treatment.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

Yearly file containing information on bacterial productivity. Samples were collected at various sites near Toolik Research Station (68 38'N, 149 36'W). Sample site descriptors include an assigned number (sortchem), site, date, time and depth.

A rock-scrubbing technique was used to collect bottom samples at several different stations with three replicates at each station in the Kuparuk River. The stations are measured relative to the 1984 phosphorus dripper. Only July sampling dates are included in this file (ACG). The samples were preserved in ethanol then picked, sorted, counted, and measured in Duluth using a NIKON MICRO-PLAN II digitizing pad.

A Surber sampler (25 X 25 cm frame fitted with a 243 um mesh net) was used to sample invertebrates at several different stations. Two replicates were taken from each station. The same sampling procedure was used for all dates. The stations were measured relative to the site of the dripper ("-" = upstream of the dripper). Samples were preserved in 4% formaldehyde and transported to Orono, Maine, where invertebrates were removed by hand under 15X magnification and then identified and counted. All values are converted to individuals per square meter.

A Surber sampler (25 X 25 cm frame fitted with a 243 um mesh net) was used to sample invertebrates on a single date at each site. Five replicates were taken from at least two riffles at each site. Samples were preserved in 4% formaldehyde and transported to Orono, Maine, where invertebrates were removed by hand under 15X magnification and then identified and counted. All values are the mean of five replicates and have been converted to individuals per square meter.

Decadal file describing the water chemistry in various lakes near Toolik Research Station (68 38'N, 149 36'W) during summers from 1990 to 1999. Chemical analyses were conducted on samples from various depths in the sample lakes either once, or multiple times during the spring, summer and fall months (May to September).

Decadal file describing the water chemistry in various lakes near Toolik Research Station (68 38'N, 149 36'W) during summers from 2000 to 2009. Chemical analyses were conducted on samples from various depths in the sample lakes either once, or multiple times during the spring, summer and fall months (May to September).

Decadal file describing the water chemistry in various lakes near Toolik Research Station (68 38'N, 149 36'W) during summers from 2010 to 2014. Chemical analyses were conducted on samples from various depths in the sample lakes either once, or multiple times during the spring, summer and fall months (May to September).

Decadal file describing the water chemistry in various lakes near Toolik Research Station (68 38'N, 149 36'W) during summers from 1983 to 1989. Chemical analyses were conducted on samples from various depths in the sample lakes either once, or multiple times during the spring, summer and fall months (May to September).

The Kuparuk River has been the central research location on the impact of added phosphorus to arctic streams. Additions of phosphorus occred since 1983. Today, 4 specific reaches show certain characteristics based on the years that they recieved fertilization. Whole Stream Metabolism is a way to quantify primary production of this stream system. Calculations were done using dissolved oxygen, discharge, stage, light and temperature measured by sondes and other equipment strategically deployed in the field at locations to quantify each of the unique stream reaches.

Zooplankton density, in number per liter, was taken with a 30 cm diameter plankton net with a 335 um mesh plankton netting. All samples were collected from Toolik Lake and the lakes near the Toolik Field Station, Arctic LTER from 1993-2002.

NOTE: In versions pervious to 3 the dates for 1994 and 1995 were WRONG.

A study investigating the mechanisms that control long-term response of tussock tundra to fire and to increases in air temperature, CO2, nitrogen deposition and phosphorus weathering. The MBL MEL was used to simulate the recovery of three types of tussock tundra, unburned, moderately burned, and severely burned in response to changes in climate and nutrient additions. The simulations indicate that the recovery of nutrients lost during wildfire is difficult under a warming climate because warming increases nutrient cycles and subsequently leaching within the ecosystem.

The data set describes stable carbon and nitrogen isotopes and carbon and nitrogen concentrations from an August 2012 pluck of a fertilization experiment begun in 2006. Fertilization was with nitrogen (N) and phosphorus (P). Fertilization levels included control, F2, F5, and F10, with F2 corresponding to yearly additions of 2 g/m2 N and 1 g/m2 P, F5 corresponding to yearly additions of 5 g/m2 N and 2.5 g/m2 P, and F10 corresponding to yearly additions of 10 g/m2 N and 5 g/m2 P. After harvest, plants were separated by species and then by tissue.

Arthropods (spiders and insects) were collected three times during the 2013 summer using pitfall traps and vacuum sampling in plots fertilized with Nitrogen and Phosphorus for 24 years, and in control plots, in an experiment established near Toolik Field Station, Alaska. Pitfall traps were placed for 48-hour intervals; vacuum samples were taken in a 1m2 area. Collected invertebrates were counted and identified to order or family.

In contribution to the Arctic Observing Network (AON), the researchers have established two observatories of landscape-level carbon, water and energy balances at Imnaviat Creek, Alaska and at Pleistocene Park near Cherskii, Russia. These will form part of a network of obervatories with Abisko (Sweden), Zackenburg (Greenland) and a location in the Canadian High Arctic which will provide further data points as part of the International Polar Year. This particular part of the project focuses on simultaneous measurements of carbon, water and energy fluxes of the terrestrial landscape at hour

The Biocomplexity Station, now known as the Tussock Station, was established in 2005 to measure landscape-level carbon, water and energy balances at Imnavait Creek, Alaska. The station is now contributing valuable data to the AON project that was established at two nearby stations. These will form part of a network of observatories with Abisko (Sweden), Zackenburg (Greenland) and a location in the Canadian High Arctic which will provide further data points as part of the International Polar Year. This particular part of the project focuses on simultaneous measurements of carbon, water an

In contribution to the Arctic Observing Network (AON), the researchers have established two observatories of landscape-level carbon, water and energy balances at Imnavait Creek, Alaska and at Pleistocene Park near Cherskii, Russia. These will form part of a network of observatories with Abisko (Sweden), Zackenburg (Greenland) and a location in the Canadian High Arctic which will provide further data points as part of the International Polar Year. This particular part of the project focuses on simultaneous measurements of carbon, water and energy fluxes of the terrestrial landscape at hour

In contribution to the Arctic Observing Network (AON), the researchers have established two observatories of landscape-level carbon, water and energy balances at Imnavait Creek, Alaska and at Pleistocene Park near Cherskii, Russia. These will form part of a network of observatories with Abisko (Sweden), Zackenburg (Greenland) and a location in the Canadian High Arctic which will provide further data points as part of the International Polar Year. This particular part of the project focuses on simultaneous measurements of carbon, water and energy fluxes of the terrestrial landscape at hour

In contribution to the Arctic Observing Network (AON), the researchers have established two observatories of landscape-level carbon, water and energy balances at Imnaviat Creek, Alaska and at Pleistocene Park near Cherskii, Russia. These will form part of a network of obervatories with Abisko (Sweden), Zackenburg (Greenland) and a location in the Canadian High Arctic which will provide further data points as part of the International Polar Year. This particular part of the project focuses on simultaneous measurements of carbon, water and energy fluxes of the terrestrial landscape at hour

The Biocomplexity Station, now known as the Tussock Station, was established in 2005 to measure landscape-level carbon, water and energy balances at Imnavait Creek, Alaska. The station is now contributing valuable data to the AON project that was established at two nearby stations. These will form part of a network of observatories with Abisko (Sweden), Zackenburg (Greenland) and a location in the Canadian High Arctic which will provide further data points as part of the International Polar Year. This particular part of the project focuses on simultaneous measurements of carbon, water an

In contribution to the Arctic Observing Network (AON), the researchers have established two observatories of landscape-level carbon, water and energy balances at Imnaviat Creek, Alaska and at Pleistocene Park near Cherskii, Russia. These will form part of a network of obervatories with Abisko (Sweden), Zackenburg (Greenland) and a location in the Canadian High Arctic which will provide further data points as part of the International Polar Year. This particular part of the project focuses on simultaneous measurements of carbon, water and energy fluxes of the terrestrial landscape at hour

In contribution to the Arctic Observing Network (AON), the researchers have established two observatories of landscape-level carbon, water and energy balances at Imnaviat Creek, Alaska and at Pleistocene Park near Cherskii, Russia. These will form part of a network of obervatories with Abisko (Sweden), Zackenburg (Greenland) and a location in the Canadian High Arctic which will provide further data points as part of the International Polar Year. This particular part of the project focuses on simultaneous measurements of carbon, water and energy fluxes of the terrestrial landscape at hour

This material is based upon work supported by the National Science Foundation under Grants #DEB-1637459, 1026843, 9810222, 9211775, 8702328; #OPP-9911278, 9911681, 9732281, 9615411, 9615563, 9615942, 9615949, 9400722, 9415411, 9318529; #BSR 9019055, 8806635, 8507493. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.